Dump-grate-operating mechanism



June 10, 1930. c. F. MILLER DUMP GRATE OPERATING MECHANISM 2 Sheets-sheer 1 Filed Got. 17, 1928 lNvENToR ChullRsEMiller WITNESS ATTORNEY June 10, 1930. C, F, MILLER 1,762,405

DUMP GHATE OPERATING MECHANISM Filed Dct. 17, 1928 2 Sheets-Sheet 2 'INVENTOR Charles EMilIer BY Q" ATTORNEY Patented June 10, 1930 UNITED STATES PATENT OFFICE VANIA, ASSIGNOR TO WESTINGHOUSE ELEC- A CORPORATION OF PENNSYLVANIA DUMP-GRATE-OPERATING MECHANISM Application filed October 1 My invention relates to progressive feed stolrersand particularly to hand-operated mechanism for operating the dump grates, and it has for an object to provide such a 5 mechanism which is of improved construction and arrangement of parts.

In hand-operated dump grate mechanism heretofore known to me, numerous auxiliary devices such as, for example, handbperated catches, levers, etc. have been utilized to engage and hold parts of the mechanism so as to maintain the dump grate m its raised position'. Obviously `in operating such mechanism the operator has to rst disengage the holding device and then lower the grate by a separate operation. Also one operation is required to raise the grate and another is required to place the holding device in operating position.

More particularly, therefore, it is an object of this invention to provide a handoperated dump grate operating mechanism which can be operated to either raise or lower the dump grate by the simple turning of a handle, and one which will maintain the dump grate in either its raised or lowered position without the use of `auxiliary apparatus requiring operation other than that of turning the handle.

Other objects of my invention are comprised in the provision of a hand-operated dump grate operating mechanism which requires a minimum amount of power to operate, which is highly compact in form, cheapto manufacture, simple in construction, and onewhich can be readily assembled and disassembled.

These and other objects are effected by my invention, as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a. part of this application, in which:

Fig. 1 is a fragmentary sectional View showing a preferred application of my invention; i

Fig. 2 is an enlarged fragmentary elevational view showing details of the dump grate Operating mechanism;

7, 1928. Serial No. 313,135.

Fig. 3 is a sectional view taken on line III-III of Fig. 2;

Fig. t is a sectional view taken on line IV-IV of Fig. 3 showing the dump grate in raised position; and

Fig. 5 is a view similar to Fig. 4 showing the dump grate in lowered position.

According to one aspect of my invention, I provide a Stoker having a dump grate mechanism and a shaft for operating the dump grate and including an extension pro jecting exteriorly of the furnace.

I provide an improved form of operating mechanism for the dump grate. The operating mechanism is carried by a suitable supporting structure secured to the outside of the furnace adjacent the extension of the dump grate shaft. The operating mechanism includes a hand operated speed reducing mechanism and a motion transmitting mechanism connecting the speed reducing mechanism to the dump grate shaft. I also provide an abutment on the supporting structure which is so constructed and arranged with respect to the motion transmitting mechanism and the dump grate that the weight of the dump grate in raised po sition will act to urge portions of the motion transmitting mechanism against the abutment to hold the dump grate in such raised position.

According to another aspect of my invention, I provide a hand operated speed reducing mechanism for operating the dump grate comprising two stages of speed reduction. The pinion of the first stage of reduction is operated by a hand crank and the gear of the second stage is connected to the motion transmitting mechanism. The pinion of the first stage and the gear of the second stage move about coincident axes and the gear of the first stage and the pinion of the second stage also move about coincident axes. The gears are carried by a supporting frame structure including a base plate and spider frame se cured to the `base plate. As the `axes of movement of the two stages are coincident, and as the entire mechanism` is supported by single supporting structure, it will be plate 21.

i mechanism comprises readily seen that the above construction provides an extremely simple and highly compact arrangement.

Referring now in detail to the construction illustrated and particularly to Fig. 1, it will be seen that I have shown, by way of example, a furnace having installed therein, a stoker` of the single retort type. The stoker comprises a retort 10, a fuel hopper 11, a dump grate 12, and an overfeed grate surface 13 extending from the upper lateral edge of the retort to the dump grate.

' In the operation of the stoker, fuel is fet into the retort from the hopper by any suitable mechanism and it is discharged from the retort and burned surface. Periodically the refuse is dumped by lowering the dump grate 12 as will be readily understood.

The dump grate comprises a plurality of grate members 14 which are fixed to a transversely extending shaft 15 which latter is supported for rotary movement by bearing brackets 15a. The dump grate is moved to raised and lowered positions by means of an improved dump grate operating mechanism, at 16, which is arranged exteriorly of the furnace and is operatively connected to an extension 17 of the dump grate shaft l5.

Referring now to Figs. 2 to 5, inclusive, it will be seen that the dump grate operating mechanism includes a'supporting structure 18 carried by .the furnace wall, a handoperated speed-reducing mechanism 19 car,- ried by the support-ing structure and a power-transmitting mechanism 20 connecting the speed-reducing mechanism with the extension `17 vof the dump grate shaft.

The supporting frame structure includes al base plate 21 suitably secured tothe front wall of the furnace by bolts 22, and aspider frame 23 secured by bolts 24 to the base The spider frame 23 comprises a body portion 25 and leg portions 26, 27 and 28. The leg portions serve as a means for securing the spider frame to the base plate 21, and also as a means for maintaining the body portion 25 in spaced relation to the base plate.

As stated, the 19 is carried by the base plate speed-reducing mechanism the spider frame 23 and 21. The speed-reducing two stages of speed reduction. rIhe first stage consists of a pinion fixed to a shaft 31 and meshing with a gear 32 fixed vto a second shaft The second stage of reductioncomprises a pinion 34 fixed to the shaft 33, disposed between the spider frame and the base plate 21 and meshing with a sector gear 35 also disposed between the spider frame and the base plate. The sector gear is provided with hollow hub portions 36 having jouron the overfeed grate lbase yshown in lowered position.

meas-oe nals on their exterior surfaces, and the journals are rotatably mounted Within aligned openings provided in the body portion 25 of the spider frame and within the base plate 21. The shaft 31 has a bearing support Within the hollow ,hub portion of the sector gear y35. Theshaft 33 is rotatably mounted within aligned openings provided in the body portion 25 of the spider frame and within the Abase plate 21.

The motion-transmitting mechanism comprises a crank pin 37 fixed to the sector gear 35, a lever 38 fixed to the extension 17 of the dump grate shaft, and a link member 39 connecting the crank pin 37 with the outer end of the lever 38.

The leg portion 26 of `the spider frame is provided with a pair of .abutment surfaces 40 and 41, respectively. The purpose of .these abutment surfaces is to lengage the sides of the sector gearV when the dump grate is in extreme positions so as to prevent any further movements of the sector Gear. b A handle 42 .is fixed to the outer end of the shaft 31 and provides a means for turning this lshaft so -as to operate the dump grate operating mechanism.

A cover 43 is detachably secured to the plate 21 and serves as a means for enclosing the operating mechanism. Tliefcover is provided with an opening 50, through which portions of the link Imember 39 and lever 38 extend.

In Figs. 2 and 5 the dump `grate 12 is In this position, one side of the sector gear engages the abutment 40 provided by the leg portion 26 of the spider frame. As stated above, this abutment serves as a means for limiting further movement of ythe ldump grate in that direction. f

In order to raise the dump grate, the handle 42 is moved in a counter-clockwise direction which vresults in a `counter-clockwise movement of the pinion 30, a clockwise movement of the gear 32 and pinion 34, and a counter-clockwise movement of the sector 35.

In Fig. 4, I have shown the dump vgrate operating mechanism asbeing in raised position.l It will be observed that the abutment 41 is engaged by the sector gear-35, and vthat the axis of the pivotal connection between the link member 39 and the .crank pin 37 on the sector gear, is spaced a slight distance above a straight linel extending through the axis of movement axis of the pivotal connection between the link member 39 and the lever 38.

Tith the grate in this position, it will be seen that the force creat-ed by the weight of the dump grate 12 is transmitted through the shaft 17, lever 38 and link member '39 to urge the crank pin further away from of the sector gear and thel the imaginary line referred to above. This Will result in the side of the sector gear being urged against the abutment il so as to maintain the dump grate in its raised position.

'It Will thus be seen that the construction and arrangement of the sector gear 35, crank pin 37, link member 39 and lever 38, with respect to the abutments 40 and il provides an extremly effective arrangement for automatically maintaining the dump grate in either raised or lowered position. lt Will also be noted that these operations are effected by the simple turning of the handle and that no auxiliary devices are necessary for maintaining the dump grate in its raised and lowered positions.

As the tivo stages of speed-reduction move about coincident axes, and as the speed reduction mechanism as a Whole is carried by a supporting frame structure Which includes a base plate 21 and a spider frame 23, it will be readily seen that I have provided a highly compact and extremely simple ar rangement for raising and lowering the dump grate by hand.

In the-above description and in the accompanying claims, l have referred to a speed-reducing mechanism 19 and a motiontransinitting mechanism 20. In the accompanying dravving, it Will be observed thatthe sector gear performs tivo functions, and its structure forms a part of both the motion-transmitting mechanism and the speedreducing mechanism. That is to say the sector gear serves as the last gear in the speed-reducing mechanism, and also this gear serves as a part of a crank for transmitting the power to the link member 39.

lVhile I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptibie of various changes and modifications, Without departing from the spirit thereof, and l desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

That l claim is:

l. In a Stoker, the combination with a dump grate and means for supporting the dump grate for movement about an axis; of mechanism for effecting the rotation of the grate so as to raise and lower the same; the mechanism comprising an operating lever connected to the dump grate, a cra-nk mounted to move about a fixed axis, a link pivotally connected at one end to the lever and pivotally connected at its other end to the crank, a hand-operated speed-reducing mechanism for effecting the movement of the crank about its axis, and an abutment for limiting the 'movement of said crank; the dump grate, lever, crank, connecting link and abutment being so constructed and arranged With respect to cach other that when the dump gra-te is in its raised position, the axis of pivotal connection between the link and crank will be spaced a slight distance from a line extending through both the axis of rotation of the crank and the axis of pivotal connection of the link and lever, and the Weight of the dump grate will act to urge the crank against the abutment.

2. In a Stoker, the combination with a dump grate and means for supporting the grate for movement about an axis; of a supporting structure; a handbperated .speed reducing mechanism carried by` said supporting structure and including a large gear mounted to move about a fixed axis, a pinion meshing with the large 'gear and mounted to move about a fixed axis, a second large gear operatively connected to the pinion for driving the latter and mounted to move about an axis coincident with the axis of movement of the pinion, a second pinion meshing with the second large gear and mounted to move about an axis coincident With the axis of movement of the iirst large gear, and hand-operated means for moving the second pinion about its axis of movement; a motion-transmitting mecha nism connecting the first large gear With the dump grate for moving the dump grate about its axis of movement; the motiontransmitting mechanism including crank means operatively connected to the first large gear; means providing an abutment for limiting the movement of the crank means in one direction; the motiontransmitting mechanism, dump grate and abut ment means being so constructed and arranged that the dump grate in raised position will cause the crank moans to be urged against the abutment means.

3. ln a Stoker, the combination Witha dump grate and means for supporting the dump grate for movement about an axis; of a supporting structure including a base `plate and a spider frame; the spider frame including a body portion spaced from the base plate and leg portions providing means for securing the spider to the base plate; a hand-operated speed-reducing mechanism carried by the supporting structure and including a sector gear disposed between the base plate and the body portion of the spider and having a hollow hub portion providing journals on its exterior surface, the journals having bea-ring supports in the base plate and body portion of the spider respectively; the hand-operated speed-ra ducing mechanism also including a shaft having a bearing supported in the base plate and spider respectively, a pinion xed to the shaft and meshing with the sector gear, the pinion being disposed between the base plate and the spider frame, a large gear fixed to the shaft, a second shaft extending Cil loo

Within 'the vhub of the sector gear and being supported t0 rotate With respect to the sector gear, a second pini-on fixed to the second shaft and meshing With the large gear, and

Vhand-operated means for rotating the second shaft; motion-transmitting mechanism connecting the sector gear and the dump grate in such a manner that movements of the sector gear will cause the dump grate to be raised and lowered about its axis of support; the motion-transmitting mechanism including a crank pin secured to the sector gear and a link secured to the crank pin; the dump grate, the supporting structure, the speed-reducing mechanism and the motion-transmitting mechanism being so constructed and arranged that the Weight of the dump grate When in raised position, acts to urge the sector gear against one of the 'leg portions of the spider frame.

4. In a stoker, the combination With a dump grate and means for supporting the dump grate Vfor movement about an axis; of a supporting frame structure including a base plate and a spider frame; the spider frame including a-body portion and a leg portion for securing the body portion to the base plate; motion-transmitting mechanism for raising and lowering the grate; said motion-transmitting mechanism including a crank disposed between the base plate and the spider frame and supported for movement about a iXed aXis the base plate and spider frame; one of the legs of the spider frame forming an abutment for limiting the movement of the crank in one direction; and speed-reducing mechanism for moving the crank about its support;` the motion-transmitting mecha nism, dump grate and the leg form-ing the abutment being so constructed and arranged that the Weight of the dump giratel acts to urge the crank against such leg when the grate is in raised position.

In testimony whereof I have hereunto subscribed my name this 9th day of October,

CHARLES F. MILLER.

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